Diabetes mellitus (DM), also known as diabetes, is a group of metabolic diseases that cause long-lasting hyperglycemia symptoms in humans as well as some other mammals, such as mice. These hyperglycemia symptoms include high blood sugar levels (i.e. >140 mg/dL), frequent urination, increased thirst and hunger, and more severely diabetic ketoacidosis and hyperosmolar coma. Long-term hyperglycemia often leads to heart diseases, stroke, kidney failure, ulcers in extremities, eye damages and obesity. There are two types of diabetes: type-I DM results from lack of sufficient insulin production in pancreas (or called insulin-dependent DM; IDDM), and type-II DM results from body's failure to respond to insulin (or called insulin resistance; non-insulin-dependent DM; NIDDM). For treatment, type-I DM must be managed with insulin injections while type-II DM may or may not be treated with insulin, depending on the pathological causes of insulin resistance.
Current medications for type-II DM can be categorized into five groups: first, drugs increase insulin production in pancreas, such as Sulfonylureas, Meglitinides and Stitagliptin; second, drugs decrease sugar production in liver, such as Metformin; third, drugs increase sugar excretion via urine, such as Canagliflozin; forth, drugs reduce insulin resistance in fat tissues and muscles, such as Thiazolidinediones; and last, drugs delay and/or reduce sugar absorption in intestines, such as alpha-glucosidase inhibitors. However, due to the kinetic properties of these drugs directed against certain natural metabolic pathways of the body, they often present various degrees of side effects, including hypoglycemia (Sulfonylureas, Meglitinides, Stitagliptin and alpha-glucosidase inhibitors), kidney failure (Metformin and Canagliflozin), heart failure (Metformin and Thiazolidinediones), gastrointestinal problems (Metformin and alpha-glucosidase inhibitors), edema and anemia (Thiazolidinediones). In some worst cases, death has been reported.
To prevent the lethal problems of kidney and heart failure, the best way of treating type-II diabetes is to delay and reduce sugar absorption in intestines; yet, without losing the supply of energy. The current anti-diabetic drugs of this kind such as alpha-glucosidase inhibitors function through inhibition of intestinal enzymes that convert carbohydrates into monosaccharides and hence can block sugar uptake in intestines. Nevertheless, the undigested carbohydrates may then interact with colon bacteria to cause gastrointestinal problems, such as flatulence and diarrhea. From the beneficial view, this side effect may help to reduce obesity; yet, the drawback is that blocking sugar uptake also means loss of energy supply to the body. As a result, overdose of alpha-glucosidase inhibitors can lead to acute hypoglycemia in diabetes patients.
Recently, it is further noted that the use of sugars and sugar substitutes such as artificial sweeteners may worsen the sugar intolerance conditions of Diabetes mellitus in patients (Suez et al., (2014) Nature in press, doi:10.1038/nature13793).
In sum, there is currently no safe drug agent or sugar substitute that can treat type-II DM while still maintaining the supply of normal body energy. Therefore, it is highly desirable to have a novel anti-diabetic composition that is able not only to reduce sugar absorption in intestines but also to provide an alternative energy source to the body.